On Aug 11, 2006, at 10:26 AM, Joe Cooley wrote:
> I recently inspected ssl packets from the following
apps:
>
> firefox 1.5.0.6
> safari 2.0.4 (419.3)
> curl 7.15.4 with OpenSSL/0.9.7i
>
> I found that they list the following cipher suites
during the client
> hello handshake protocol:
>
> (snippets from ethereal -V output...)
<snip>
> Safari only seems to support DES, 3DES, and RC4
ciphers. My question
> is this: should I be concerned about privacy when
*_RC4_* is the
> negotiated suite, i.e., in my tests, safari used
> TLS_RSA_WITH_RC4_128_SHA? Firefox and curl used
> TLS_DHE_RSA_WITH_AES_256_CBC_SHA.
RC4 when used correctly (which I believe it is in TLS)
should not
concern you much. What should concern you, however, is that
Apple
has chosen to include a testing/debug NULL cipher in their
production
(and completely unmodifiable w/o recompiling
System.framework)
cipherlist:
> Cipher Suite: TLS_RSA_WITH_NULL_MD5 (0x0001)
This means that a malicious server can negotiate Safari into
using no
encryption at all, while still providing all the GUI
feedback of a
secure SSL connection...
For fun, fire off this command and visit localhost:4433 from
both
firefox and safari, and look at the packet dumps in ethereal
(use any
snakeoil server.* you have handy):
/usr/local/bin/openssl s_server -cert server.crt -key
server.key -www
-cipher
'AES:TLSv1:ALL:NULL:!RC4-SHA:!RC4-MD5:!DES-CBC3-SHA:!DES-CB
C-
SHA:!EXP-RC4-MD5:!EXP-DES-CBC-SHA:!EXP-RC2-CBC-MD5'
I filed a bug with Apple on this back in February, I
encourage others
to do so as well at http://radar.apple.com.
Ask them to include the
AES ciphers while you're at it, it's only been 5 years or
so since it
was standardized...
Thanks,
Eric
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